Writing instrument



Nov. 24, 1953 a. D. SMITH ET AL 2,660,151

WRITING INSTRUMENT Filed April 28, 1948 4 Sheetg-Sheet l VENTOR BLfl/YCl/ARD JM/r ATTORNEYS Nov. .24, 1953 B. D. SMITH ET AL WRITING INSTRUMENT Q RE INVENTORS A/VC/lfl/FD D. 301/77! AVID I? BERRY 4 Sheets-Sheet 2 Filed April 28, 1948 4 TTOIF/YEVS 24} 1953 B. D. SMITH ET AL 2,660,151

WRITING INSTRUMENT Filed April 28, 1948 4 Sheets-Sheet 4 1N VEN TORS I 9 BLAIVCIMRD :01/

1 m Mp -0404,16

ATI'OIPIYEVJ Patented Nov. 24, 1953 2,660,151 wiurmo msratm ENT Blanchard D. Smith and David R. Berry, Atlanta, Ga.-, assignors to Scripto, Inc., a corporation of Georgia Application April 28, 1948, Serial No. 23,758

2 Claims; (01. 12.0-42.4) 7

This invention relates to writing instruments, and more particularly to writing instruments of the type incorporating a ball applicator and to method and means for forming writing instruments of this type.

Writing instruments having ball applicators are well known. Such writing instruments are commonly formed with a barrel arranged to contain a supply of so-called dense or "plastic ink, and means for mounting the ball applicator.

so that it is free to rotate or roll at the writing end of the barrel for transferring the ink to a writing surface.

One of the major difiiculties in forming a writing instrument of this sort is the problem of mounting the ball applicator for proper rolling action. Various forms of inte'rfitting sleeves and machined sockets and the like have heretofore been employed as a mounting means, but in each prior instance of which we are aware the mounting means used have required the maintenance of very close tolerances that were extremely difficult to meet in production operations.

According to the present invention this diffrculty is avoided entirely by moulding the mount ing means for the ball applicator directly in the barrel at the time the barrel is formed. The barrel can be formed of molded plastic in this manner by the usual injection molding processes, or the mounting means might be molded by die casting, if desired, in which case a metal writing tip portion for the barrel could be formed containing the mounting means.

The present invention is described further be-- low in connection with the accompanying drawing, in which:

Fig. 1 shows related elevations of a cap and barrel for a writing instrument incorporating the present invention;

Fig. 2 is a central longitudinal section of the writing instrument shown in Fig. 1 with the cap in place on the barrel;

Fig. 3 is a section taken on the line 3 3 in Fig. 2;

Fig. i is an enlarged sectional detail of the writing tip portion of the barrel; 4

Fig. 5 is a section taken on the line 5 5 in Fig. 4;

Fig. 6 is a fragmentary sectional detail illus= trating a form of molding apparatus for use in forming the writing instrument of the present invention;

Fig. 7 is a fragmentary sectional detail of an alternative arrangement of the molding appara tus shown in Fig. 6;

Fig. 8 is an enlarged sectional detail ofa modified form of writing tip portion for the barrel; and

Fig. 9 is a fragmentary sectional detail of a molding apparatus for use in forming a writing instrument incorporating a writing tip portion of the type shown in Fig. 8.

As illustrated in Fig. 1 of the drawing, the writing instrument of the present invention comprises a barrel it having a writing tip portion H, and a cap 42 for covering the writing tip portion II of the barrel Ill when the writing instru'- ment is not in use. The barrel it is preferably formed of molded plastic, although as previously mentioned a writing tip portion might be die cast for association with a barrel of any suitable material. The cap I2 is preferably formed of metal.

The structural arrangement of the barrel it is illustrated more in detail in Fig. 2 of the drawing. As shown in Fig. 2, the upper end or body portion of the barrel IE1 is formed with a tubular bore l3 so that this portion of the barrel may be adapted as a reservoir for ink. For this purpose, the tubular bore i3 is fitted with a plug as shown at I l having a capillary bore l5 opening at its inner end and extending to a flared portion it from which a bore ll of enlarged diameter opens at the outer end of the plug l4. This form of the plug 14 provides for admission of air to the ink reservoir formed by the tubular bore it, but prevents leakage of ink when the barrel in is inverted.

The top end portion of the barrel la is reduced in diameter to receive a cap member [8 which covers the open end of the tubular bore Iii. The cap member I8 is fixed on the barrel in by dimpling as indicated at [9, or the like, and is formed with an aperture 2!] allowing admission of air to the tubular bore [3.

The tubular bore l3 extends toward the writing end portion I l of the barrel It to join a longitudinal feed duct 2|. The feed duct 2! has a cross-sectional form of capillary dimensions shaped in a pattern including at least three radial channels arranged symmetrically with respect to the longitudinal axis of the barrel it) (compare Figs. 3 and 5). A pattern of this sort provides for good distribution of ink by the feed duct El to the ball applicator 22 mounted at the writing end of the barrel It. In some instances more than three radial channels may be desirable although we have found that the arrangement of three channels as shown in the drawing provides a good balance between ink distribution and strength of the writing tip portion I I.

The ball applicator 22 is mounted in a concave socket 23 moulded in the extending end of the writing tip portion ll of the barrel Ill, and the feed duct 2| opens in this concave socket 23 for feeding ink from the tubular bore I3 to the ball applicator 22. As shown best in Fig. 4 of the drawing, the concave socket 23 is formed to define a major portion of a sphere so that it surrounds the ball applicator 22 in retaining relation. That is, the concave socket 23 is moulded with a reentrant form so that it is adapted to contain more than half of the spherical surface of the ball applicator 22 and thus retain the ball applicator 22 in association with the barrel it While allowing partial projection for writing. In writing, the ball applicator 22 rotates or rolls in the concave socket 23 in the usual manner to pick up ink delivered by the feed duct 2| and transfer it to a writing surface.

In order to reenforce the concave seat 23, a shell member 24 is molded as an insert in covering relation at the tip of the writing end portion H of the barrel It The shell member 24. :is preferably shaped to form a shouldered tip on the writing end portion ll so that it can be securely anchored as an insert in the writing end portion II to prevent any leakageof ink at this point.

The cap i 2 for covering the writing end portion H has a generally cylindrical form adapted for a friction fit on the writing end portion H of the barrel [6. As shown in the drawing, the writing end portion ll is suitably tapered and may be reduced in diameter so that when the cap !2 is in place its exterior surface will be flush with that of the main body portion of the barrel It as illustrated in Fig. 2. The cap 12 is further formed with an external circumferential roove 25 for securing a pocket clip 25 in place. The pocket clip 26 is formed with a split mounting band 2'! adapted for disposition in the circumferential groove 25 so that it may be slipped over the top end of the cap [2 and snapped in the groove 25 to assemble the pencil clip 25 on the cap !2 (compare Figs. 1 and 2).

The method and means employed according to the present invention for forming the concave socket 23 to mount the ball applicator 22 as described above is illustrated in Fig. 6 of the drawing which shows a fragmentary sectional detail of an injection mold for forming the barrel H). The mold cavity is represented by the section lining at 28 formed with a suitable air escape channel 23; the reference numeral 3!! indicates a mandrel associated with the mold for forming the internal configuration of the barrel Hi, namely, the feed duct 2! and the tubular bore l3; and 3! is a pin carrying a forming element 32 which provides a mold surface for the concave socket 23.

In the molding apparatus shown in Fig. 6, the forming element 32 is integral with the pin 3!, and is disposed in the mold 28 in correspondence with the operating disposition of the ball applicator 22 at the writing end portion ll of the barrel Hi. The forming element 32 is shapedto define a major portion of a sphere beyond the face of the pin 3! so that the concave socket 23 will be formed with a corresponding shape. The extending end of the mandrel 30 has a complementary shape and is disposed so that when the mold 23 is closed it will extend in contact with the forming element 32. Also, the mandrel 30 is tapered at its extending end in spaced relation with the shell member 24, but has a main body 4 of sufficient diametric extent to contact the shell member 24 and position it in the mold 28.

Accordingly, with the mold 28 closed, injection of plastic molding material will result in forming the plastic material around the forming element 32 to mold the concave socket 23, and as the mandrel 30 extends in contact with the forming element 32, the feed duct 2! will be molded to open in this concave socket 23. Also, with the shell member 24 positioned in the mold 28 as described above it is molded as an insert in covering relation on the writing end of the barrel i0 during the molding operation.

After the molding operation, the mold 28 may be opened to remove the barrel H] formed in this manner. The elasticity of the molded plastic will allow this removal without deforming the concave socket 23. A ball applicator 22 may then be disposed in the concave socket 23 and, after trimming the tip of the writing end portion H as indicated by the dotted lines at 33 in Fig. 6, the other elements described above may be assembled with the barrel In to form the writing instrument of the present invention.

This method of forming the barrel l8 allows great flexibility in selection of the molding material to be used. In general, any plastic material which is not attacked or corroded by ink may be used. There appears to be some advantage in using a thermoplastic material, such as cellulose acetate, because the elastic properties of these materials apparently allow the concave socket 23 to give when writing pressure is placed on the ball applicator 22 so that a clearance for ready feeding of ink is always obta ned adjacent the point of writing pressure. However, with the less elastic thermosetting materials the forming element 32 may be made slightly larger than the ball applicator 22 so as to obtain an equivalent effect; and with metals, which might be used in die casting, the forming element 3| might be formed with a raised ring configuration (not shown) to form an annular channel in the concave socket 23 to provide a distribution duct for ink fed from the feed duct 2|.

An alternative arrangement for forming the concave socket 23 is shown in Fig. 7 of the drawing in which the mold cavity is illustrated again by section lining at 34 with an air escape channel at 35, and the mandrel for forming the internal configuration of the barrel i3 is indicated at 33. In this case, however, the ball applicator 22 itself is positioned in the mold 36 against a stop pin 31 by engagement with the extending end of the mandrel 36. The stop pin 37 is recessed as shown so that a major portion of the surface of the ball applicator 22 is disposed in the mold 3 to form the concave socket 23 in the same general manner as described above. Also, the mandrel 36 is arranged for positioning the shell member 2 so that it is molded as an insert as described above. After molding the tip of the writing end portion H is trimmed at 38 and the barrel in is assembled with the other writing elements of the writing instrument as before. This arrangement has the advantage of molding the barrel in with the ball applicator in place, but it is less flexible as to the selection of molding material to be used because plastics have a tendency to shrink upon cooling so that a material having good elastic properties should be used in order to provide for good ink distribution when the barrel it is formed in this manner.

, A modified embodiment of the writing instrument of the present invention is illustrated in Fig. 8 of the drawing. In this embodiment a ball applicator 38 is mounted at the writing end por tion 39 of the writing instrument in a concave socket 46 and is retained in place by a metal shell member 4| molded as an insert in covering relation on the writing end portion 39. The shell member 4| has a truncated conical form so that it is open at its tapered end to allow partial projection of the ball applicator 38 for Writing. A feed duct 42 opening into the concave socket 40 is provided, in the same general form a in the first embodiment described above, for feeding ink to the ball applicator 38.

The method and means for forming this embodiment of the writing instrument is illustrated in Fig. 9 in which the mold cavity represented by the section lining at 43 is shown fitted with an annular supporting member 44 for positioning the shell member 4! to assume a position in covering relation at the writing end portion 39 of the writing instrument to be formed in the mold 43. The mold 43 is also fitted with a stop member 45 for positioning the ball applicator 33 at the open tapered end of the shell member 4| in correspondence with its operating disposition in the writing end portion 39, and a mandrel 43 for forming the feed duct 42 is associated with the mold 43 to close on the shell member 41 and ball applicator 38 and maintain them in place against the annular supporting member 44 and stop member 45 during the molding operation. By this arrangement the ball applicator 38 forms a mold surface for forming the concave socket 40 in the Writing end portion 39 and the shell member is molded as an insert in covering relation on the writing end portion 39 for reenforcing the concave socket and retaining the ball applicator in place, which has the advantage of forming a stronger Writing tip for the writing instrument.

' We claim:

1. A writing instrument of the type incorporating a ball applicator, said writing instrument having a barrel, a concave socket at the writing end of said barrel in which said ball applicator is seated, and a longitudinal feed duct extending centrally in said barrel and opening in said concave socket, said feed duct having a cross-sectional form shaped in a pattern including at least three radial channels arranged symmetrically with respect to and opening from a common central channel, and said barrel being formed of a molded plastic material with the concave socket at the Writing end thereof shaped originally as an impression of said ball applicator and with a metal shell member disposed originally on said writing end in covering relation for supporting said concave socket and having the end thereof remote from said writing end embedded in said barrel.

2. A writing instrument of the type incorporating a ball applicator, said writing instrument having a barrel, a concave socket at the writing end of said barrel in which said ball applicator is seated, and a shell member disposed in covering relation at the writing end of said barrel for supporting said concave socket and having the end thereof remote from said Writing end embedded in said barrel.

BLANCHARD D. SMITH. DAVID R. BERRY.

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